Engine crankcase breather and oil separator



June 16, 1953 H. H. WAGNER ET AL.

ENGINE CRANKCASE BREATHER AND OIL SEPARATOR Filed 001:. 25, 1952 ml W E fim w 3 8 9 a 1 W 3 a Z wfl \M\ l l u. j 2 a 1F w 2 V w W x a a M w a w M Patented June 16, y 1953 ENGINE CRANKCASE BREATHER AND OIL 'SEPARATOR I Harold H. Wagner, Peoria, 111., andEdred B.

Williams, Indianapolis, Ind., assignors to Caterpillar Tractor 00., Peoria, 111., a corporation of California 1 Application October This invention relates to engine "crankcase breathers and oil separators for use on integral combustion engines for separating oil and dirt from the blow by gases discharging from the crankcase as a result of pressure escaping from the combustion chambers of the engine between the piston and the cylinder walls.

It is the object of the invention to provide an engine crankcase breather and oil separator which comprises two separatefiltering or sepas rating assemblies operating in series and means for collecting and returning the major portion of oil separated by the first, assembly to the crankcase, while separating and preventing. return of further oil likely to be contaminated with dust or abrasives.

A further object of the invention is to provide a device of this kind with means for directing clean blow by gases to the intake-manifold of the engine for consumption with main fuel together with additional air and so constructed that it will indicate the presence of extensive quantities of blow by gases issuing from.the crankcase.- Further objects and advantages of i the invention are made apparent in the following specification where a preferred formof the invention is disclosed in detail by reference to the accompanying drawing.

25, 1952, Serial No. 316,824 5 Claims; (01.123-119).

ladenair of the atmosphere, it is desirably collected and returned to the engine crankcase. This is accomplished by the provision of an annular chamber just beneath, the screens I9 and a tube 2| communicating between said 2 port 23 and in this manner a liquid seal is estab- The drawing is a central vertical cross section of an enginecrankcase breather and oil separator employing the present invention with an 1 air cleaner and air intake pipe which leads to the intake manifold of the engine schematically shown.

In the drawing the invention is shown as com.-

prising a pair of filtering or condensing units l0 and H. The first unit It is secured to a wall of an engine crankcase, a portion of which is shown at I2. The wall .has an opening l3 through which blow by gas is exhausted. v Cap screws, one

of which is illustrated at M, may be used for;-

supporting the assembly ill in place. The second assembly ll communicates with and is com nected with the first assembly In by any suitable means (not shown) and it has a discharge pipe 15 which leads to a pipe l6 communicating betweenaconventional air cleaner I1 and the air intake manifold of the engine (not shown).

As the blow by gas issues through the opening 13, it passes'upwardly through a central conduit l8 in the assembly l0 and then through a filter or condensing unit consisting of a stack of screens [9 of any conventional kind. Since the oil collected or condensed by the screens l9 has not been contaminated by mixture with dust lished to prevent blow by gas from passing upwardly through the tube '2 l The relatively clean blow by gas which passes the screens l9 next passes through a central chamber 25 in the second filter assembly H and within the top of the I quired for the passage of the normal quantity of blowby gas issuing from the crankcase of the engine and since it is in communication with the partial vacuum in the, intake manifold of the engine, it is desirable to provide for additional ormake up air to supplement the gases passing through the pipe l5. this, thefilterassembly II has a space 35 be- To accomplish tween the lower half 3| of its housing and the upper half 32. The upper half is removably secured inplace by a central threaded stud 33 which fits a threaded boss 34 at the upper end element 29 for the purpose of removing, dust and abrasives borne by it. This passage 35 also serves as a breathing passage for the engine crankcase which takes in air, for example, when The air entering.

sives, the oil which they remove from the gas passing through them as it flows toward the engine is unfit for return to the engine crankcase in the manner of the oil from the filter screens l9. Therefore, any oil draining from the filters 28 and 29 is received by an annular trough a portion of which is shown at; 31 inf-the lower end of the filter assembly II and drains by wayof the passage 30 and a port 38 therein into chamber 39 which surrounds the lower portion of the gas conduit l8 in the filter assembly l; A; drain plug 40 is provided adjacent the bottom: of the chamber 39 to enable the contaminated oil therein to be drawn off periodically.

The breather and oil separator of the present invention has the advantage that it serves to direct clean gas containing some combustible crankcase, two communicating filter assemblies arranged in series to receive gas from said openins; mean to collect oil separated from the gas passing through the first assembly and to return products to the intake manifold ofzathe engine by which it will be consumed. It also has the advantage of saving and returning to theeng'ine the cleaner oil that is removed from the gas while at the same time preventing return-to-theengine of that portion of the oil which may be -'contar'- ni"- mated with abrasive substances. While the airintake 36 serves as a breather opening for the crank case and also admits make up air during engine operation, it has the further-function of indicating excessive wear to the engine operator. For example, when the piston rings and the cylinder liners wear to the extent that an excessive quantity of blow by gas discharges from a crankcase, the capacity of the pipe P is exceeded and instead of intake air entering through the opening 36, the back pressure in the filter assembly will cause the gas to exhaust through this opening thus serving as an indication of the worn condition of the engine.

We claim:

1. In a breather for permitting the exhaust of blow-by gases from the crankcase of an in ternal combustion engine, a plurality of filters in series for extractingoil from said blow-by gases and conduits for returning said gases to the engine air intake, separate conduits for directing oil separated by the first of said filters to the engine crankcase and a reservoir for collecting oil separated from the blow-by gases by the latterin the series of filters.

2. In combination with an internalcombustio engine having abreather opening in its crankcase, two communicating filter assemblies ar it to the crankcase, and means to collect oil in the, second assembly and prevent its return to the crankcase, said second assembly havin two filter elements therein and an air inlet between said elements whereby air passing therethrough toward the crankcas wiil be filtered and air passing therethrough toward the filter outlet will be filtered.

4. In combination with an internal combustion engine having a breather opening in its crankcase, two communicating filter assemblies arranged in series to receive gas from said opening, means to collect oil separated from the gas passing through the first assembly and to return it to the crankcase, means to collect oil in the second assembly and prevent its return to the crankcase, said second assembly having two filter elements therein and an air inlet between said elements whereby air passin therethrough toward the crankcase will be filtered and air passing therethrough toward the filter outlet will be fi1- tered and means to direct gas from the filter outlet to the engine intake manifold.

5. In combination with an internal combustion engine having a breather opening in its crankcase, two communicating filter assemblies arranged in series to receive gas from said opening, means to collect oil separated from the gas passing through the first assembly and to return it to the crankcase, and, means to collect oil in the second assembly and prevent its return to the crankcase, and a liquid seal in the means for returning oil to the crankcase to prevent gas from passing therethrough in opposition to the direction of oil flow.

H. WAGNER. EDRED B. WILLIAMS.

No. references cited. 

